This paper represents partial fulfillment of a Ph.D. degree for CA in Plant Breeding and Plant Genetics at the University of Wisconsin-Madison. This work is supported by the USDA-ARS. C. Arbizu is partly funded by the National Council of Science and Technology of Perú (Concytec, by its initials in Spanish). P. Tas was partly funded by the USDA-NIFA-Organic Agriculture Research and Extension Initiative award 2011-51300-30903 (to P.W. Simon).